The present invention relates to the rasterization of graphic image files, and more particularly to apparatus for managing the raster image processing of graphic images using a plurality of queues to make efficient use of computer system resources.
In computer generated image recording, a plurality of computer generated images are rasterized for use in exposing corresponding frames of photographic film or the like. The film (or other imaging medium) can then be developed to provide, e.g., color slides or motion picture footage. Laser printers and color or monochrome copiers can also be used to record rasterized computer generated images.
To obtain the computer generated images, a user first generates a graphic image file using a computer graphics program. The graphic image file may include one or more images or frames of image data which, for example, are in a bit mapped or text (e.g., ASCII) format. The image data are processed by a raster image processor (RIP) which provides frames of raster image data for use by an output device in generating images. The output device may comprise a graphic display monitor and/or a photographic film recorder. Film recorders, such as those sold under the Solitaire.RTM. and Sapphire.RTM. trademarks by Management Graphics, Inc. of Minneapolis, Minn., USA are well known in the art. Laser printers and copiers are also commonly available output devices.
In the past, during use of such an image generation and recording system, the RIP would send one page of image data at a time to an output device that would then generate the image. This resulted in inefficient use of the output device, as the processing time associated with generating an image by the output device remained relatively constant while the time required to produce a page of raster image data varied with the complexity of the image. It would not be unusual for the output device to spend considerable time in an idle mode at times when complex images were being processed by the RIP. At other times, the RIP would be idle because the output device was already busy. There was no way to minimize the idle periods and keep both the RIP and output devices as busy as possible.
In computer systems accessed by local and wide area networks, a plurality of users may compete for the use of a graphic output device. Because of the excessive processing time required to generate raster image data, inefficient use of the output devices available via the network can result in an unacceptable response time for one or more of the various users. Further, to process different graphic image files for different output devices and end user requirements, a plurality of different RIP modules may be needed for generating raster image data. Examples of different available RIP modules include those known as "PostScript," "Targa," and "TIFF."
It would be advantageous to provide a system for managing the processing of graphic image data by different RIPs and different output devices. Such a system should minimize the amount of time that the RIPs and output devices are idle, and keep these devices as busy as possible. Such a system should also enable different graphic image files to be processed by the same or different RIPs and routed to the same or different output devices in an orderly and efficient manner. It would be further advantageous to provide such a system in which multiple instances of the same RIP, implemented by a RIP software module, could be run in parallel to concurrently process different graphic image files for the same or different output devices.
The present invention provides a system for managing the processing of graphic image files having the aforementioned and other advantages.